1. Field of the Invention
The present invention relates to a blower unit having an interior partitioned into two air passages, through which different kinds of air flow, respectively.
2. Description of Related Art
Conventionally, a blower unit having an interior partitioned into two air passages has been disclosed, for example, in JP-A-6-255341.
In this blower unit for an air conditioner for a vehicle, when the atmospheric temperature is low such as in winter season, outside air having a comparatively low humidity is introduced into one of the air passages and the outside air is blown to an inner surface of a windshield of the vehicle to attain defrosting effect while inside air having a comparatively high temperature is introduced to the other air passages to improve heating performance.
A detail of a blower unit 100 constituting the most upstream air portion in the air conditioner for the vehicle will be described briefly with reference to FIG. 18.
The blower unit 100 includes a fan casing 101 forming an air passage and a blower 102 disposed in the fan casing 101.
Air passages 104 and 105 are formed in the fan casing 101 by a partition wall 103 protruded from an inner wall. Further, suction ports 109 and 110 are formed in the fan casing 101 corresponding to the air passages 104 and 105, respectively.
The blower 102 is a centrifugal fan (Sirocco fan), which includes a first fan 106, a second fan 107 and a motor 108 for rotating the first and the second fans 106 and 107.
The first fan 106 and the second fan 107 are disposed coaxially with a rotary shaft of the motor 108 and rotated by the motor 108.
The first fan 106 is disposed in the air passage 104 to generate an air flow in the air passage 104 toward a passenger compartment of the vehicle. On the other hand, the second fan 107 is disposed in the air passage 105 to generate an air flow in the air passage 105 toward the passenger compartment of the vehicle.
An operation of the blower unit 100 described above will be described briefly. The suction port 109 communicates with the outside of the passenger compartment, and the suction port 110 communicates with the inside of the passenger compartment, so that the first and the second fans 106 and 107 are operated by the rotating the motor 108. In this way, the outside air outside the passenger compartment (hereinafter simply referred to as outside air) is introduced to the air passage 104, while the inside air in the passenger compartment (hereinafter simply referred to inside air) is introduced to the air passage 105.
By the way, it is necessary for the fan casing 101 which accommodates the blower 102 to be constituted by assembling a plurality of case members, because the fan casing 101 is molded by using a die unit and should have the shape to be released from the die unit.